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EXTRACTION OF ALUMINA FROM BAUXITE RESIDUE FOR PREPARATION OF ALUMS AND POLY ALUMINUM CHLORIDE MUCHTAR AZIZ; AGUS Wahyudi
Indonesian Mining Journal Vol 13, No 1 (2010): INDONESIAN MINING JOURNAL Vol. 13 No. 1 February 2010
Publisher : Puslitbang tekMIRA

The chemical composition of West Kalimantan bauxite is 45 pct Al2O3 and 16 pct Fe2O3 that has been extracted to produce alumina and bauxite residue (red mud). The residues contains Al2O3 20 pct and Fe2O3 about 37 pct, wich was furthermore processed by roasting or lime-soda sinterization at temperature of 800- 1100°C. The sintered product was leached with sodium carbonate solution to produce soluble sodium aluminate (2NaAlO2). The solution obtained was then precipitated to produce hydrated alumina (Al(OH)3. Hydrated alumina was then sulfateized by adding ammonium hydroxide, and followed by crystallization to produce high purity of ammonium aluminum sulfate crystals (alums). In addition, hydrated alumina was also chlorinated in stoichiometric amount at mol ratio of OH/Al = 0.5 – 1.5 to form polyaluminum chloride (PAC). The residue obtained from leaching was concentrated by 1000 gauss of magnetic separator to produce iron concentrate as a by product. As the results, sulfatation of hydrated alumina with addition of ammonium hydroxide results high grade of ammonium aluminum sulfate (NH4Al(SO4)2 .12H2O) crystals. Chlorination of hydrated alumina in stoichiometric amount at mol ratio of OH/Al = 1.0 results polyaluminum chloride (PAC) that quality is adjacent to the first type of PAC. Through the soda-lime sinter process, it can also produce iron concentrate having grade of 66 % Fe2O3 with 40 % of recovery

PRELIMINARY STUDY OF PARTICLE SIZE MEASUREMENT OF FINE PHOSPHATE ROCKS USING DYNAMIC LIGHT SCATTERING METHOD AGUS WAHYUDI; SARIMAN SARIMAN; SITI ROCHANI
Indonesian Mining Journal Vol 14, No 3 (2011): INDONESIAN MINING JOURNAL Vol. 14 No. 3 October 2011
Publisher : Puslitbang tekMIRA

Particle size measurement is an important role in the utilization of phosphate rocks for nanofertilizer. In this study, the phosphate rocks from Wonosari and Ciamis were milled by planetary ball mill (PBM) into submicron size (0.19 μm). Measurements of the submicron size were conducted using a dynamic light scattering (DLS) method, i.e. iluminating. The milled products were also compared to the milled zeolite and bentonite from the same PBM. There is a relationship between the particle milled size and its chemical composition. The correlation is interpreted as the result of different hardness in minerals content.

PREPARATION OF NANO SILICA FROM SILICA SAND THROUGH ALKALI FUSION PROCESS Agus Wahyudi; Dessy Amalia; Sariman Sariman
Indonesian Mining Journal Vol 16, No 3 (2013): INDONESIAN MINING JOURNAL Vol. 16 No. 3 OCTOBER 2013
Publisher : Puslitbang tekMIRA

Silica (SiO2) materials play an important role for industries, especially those in micron or even nano-scale size. The later has better properties and improves its quality. Nano silica is applied widely in building material, notably as a mixture of concrete. The material is also promising to be developed into amorphous nano silicon for solar cell materials. Indonesia has a lot of silica sand resources and faces a challenge to increase its quality into high product such as nano silica. Synthesizing silica nano through alkali fusion is a process that includes using the particles along with sodium hydroxide at temperature of 400-1100 °C then recrystalizing the molecules to get materials in nano size. The recrystalizing process was conducted by water leaching and filtration. The derived nano particles (gel) ranged between 40-60 nm. TEM characterization showed that the products are homoge- neous, well dispersed and has specific surface area around 157 m2/g.

PREPARATION OF MESO POROUS SILICA FROM BENTONITE BY ULTRAFINE GRINDING AND SELECTIVE LEACHING Agus wahyudi; SARIMAN SARIMAN; SITI ROCHANI
Indonesian Mining Journal Vol 13, No 1 (2010): INDONESIAN MINING JOURNAL Vol. 13 No. 1 February 2010
Publisher : Puslitbang tekMIRA

Preparation of meso porous silica from bentonite had been conducted by ultrafine grinding and leaching. The bentonite was taken from Nanggung, Bogor, West Java; it contains montmorillonite with porous struc- ture. The ultrafine grinding was carried out using planetary ball mill (PBM) in wet condition (wet milling) in methanol. Optimum milling time was reached in 30 hours and it produced 77.4 nm of particle size. The process was continued with selective leaching in sulphuric acid solution to increase the amount of SiO2 from 54.13% to 86.21%, which decreased Al2O3 and Fe2O3 content gradually from 23.09% and 7.33% to 4.96% and 0.89% respectively. The leaching process produced porous silica material with pore size 6.5 nm (meso porous); 278 m2/g of surface area and 0.75 mL/g of pore volume.

PREPARATION OF NANO SILICA FROM SILICA SAND THROUGH ALKALI FUSION PROCESS Agus Wahyudi; Dessy Amalia; Sariman Sariman
Indonesian Mining Journal Vol 16 No 3 (2013): INDONESIAN MINING JOURNAL Vol. 16 No. 3 OCTOBER 2013
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol16.No3.2013.383

Silica (SiO2) materials play an important role for industries, especially those in micron or even nano-scale size. The later has better properties and improves its quality. Nano silica is applied widely in building material, notably as a mixture of concrete. The material is also promising to be developed into amorphous nano silicon for solar cell materials. Indonesia has a lot of silica sand resources and faces a challenge to increase its quality into high product such as nano silica. Synthesizing silica nano through alkali fusion is a process that includes using the particles along with sodium hydroxide at temperature of 400-1100 °C then recrystalizing the molecules to get materials in nano size. The recrystalizing process was conducted by water leaching and filtration. The derived nano particles (gel) ranged between 40-60 nm. TEM characterization showed that the products are homoge- neous, well dispersed and has specific surface area around 157 m2/g.

PRELIMINARY STUDY OF PARTICLE SIZE MEASUREMENT OF FINE PHOSPHATE ROCKS USING DYNAMIC LIGHT SCATTERING METHOD AGUS WAHYUDI; SARIMAN SARIMAN; SITI ROCHANI
Indonesian Mining Journal Vol 14 No 3 (2011): INDONESIAN MINING JOURNAL Vol. 14 No. 3 October 2011
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol14.No3.2011.483

Particle size measurement is an important role in the utilization of phosphate rocks for nanofertilizer. In this study, the phosphate rocks from Wonosari and Ciamis were milled by planetary ball mill (PBM) into submicron size (0.19 μm). Measurements of the submicron size were conducted using a dynamic light scattering (DLS) method, i.e. iluminating. The milled products were also compared to the milled zeolite and bentonite from the same PBM. There is a relationship between the particle milled size and its chemical composition. The correlation is interpreted as the result of different hardness in minerals content.

EXTRACTION OF ALUMINA FROM BAUXITE RESIDUE FOR PREPARATION OF ALUMS AND POLY ALUMINUM CHLORIDE MUCHTAR AZIZ; AGUS Wahyudi
Indonesian Mining Journal Vol 13 No 1 (2010): INDONESIAN MINING JOURNAL Vol. 13 No. 1 February 2010
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol13.No1.2010.542

The chemical composition of West Kalimantan bauxite is 45 pct Al2O3 and 16 pct Fe2O3 that has been extracted to produce alumina and bauxite residue (red mud). The residues contains Al2O3 20 pct and Fe2O3 about 37 pct, wich was furthermore processed by roasting or lime-soda sinterization at temperature of 800- 1100°C. The sintered product was leached with sodium carbonate solution to produce soluble sodium aluminate (2NaAlO2). The solution obtained was then precipitated to produce hydrated alumina (Al(OH)3. Hydrated alumina was then sulfateized by adding ammonium hydroxide, and followed by crystallization to produce high purity of ammonium aluminum sulfate crystals (alums). In addition, hydrated alumina was also chlorinated in stoichiometric amount at mol ratio of OH/Al = 0.5 – 1.5 to form polyaluminum chloride (PAC). The residue obtained from leaching was concentrated by 1000 gauss of magnetic separator to produce iron concentrate as a by product. As the results, sulfatation of hydrated alumina with addition of ammonium hydroxide results high grade of ammonium aluminum sulfate (NH4Al(SO4)2 .12H2O) crystals. Chlorination of hydrated alumina in stoichiometric amount at mol ratio of OH/Al = 1.0 results polyaluminum chloride (PAC) that quality is adjacent to the first type of PAC. Through the soda-lime sinter process, it can also produce iron concentrate having grade of 66 % Fe2O3 with 40 % of recovery

PREPARATION OF MESO POROUS SILICA FROM BENTONITE BY ULTRAFINE GRINDING AND SELECTIVE LEACHING Agus wahyudi; SARIMAN SARIMAN; SITI ROCHANI
Indonesian Mining Journal Vol 13 No 1 (2010): INDONESIAN MINING JOURNAL Vol. 13 No. 1 February 2010
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol13.No1.2010.543

Preparation of meso porous silica from bentonite had been conducted by ultrafine grinding and leaching. The bentonite was taken from Nanggung, Bogor, West Java; it contains montmorillonite with porous struc- ture. The ultrafine grinding was carried out using planetary ball mill (PBM) in wet condition (wet milling) in methanol. Optimum milling time was reached in 30 hours and it produced 77.4 nm of particle size. The process was continued with selective leaching in sulphuric acid solution to increase the amount of SiO2 from 54.13% to 86.21%, which decreased Al2O3 and Fe2O3 content gradually from 23.09% and 7.33% to 4.96% and 0.89% respectively. The leaching process produced porous silica material with pore size 6.5 nm (meso porous); 278 m2/g of surface area and 0.75 mL/g of pore volume.

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